I have schizoaffective disorder, induced by a bad trip from marijuana. It was like the 3rd time I had tried weed, and I naively took too much. For me psychosis feels like pattern matching going on extreme overdrive, while at the same time memory goes to shit. It's truly an awful illness, and what's worse is that the current medical treatments are bad. I've been fortunate enough where I can get by on a low dose olanza…
One other possible immune system link is the relationahip between the parasite toximoplasis gondii to schizophrenia.
If I'm not mistaken that's the paper about that: